Traffic separators and traffic controls for varying the effective width of a roadway by means of vertically movable traffic separating barriers arranged to divide the traffic into equal or unequal portions are well known and have been in use for many years. For example, a U.S. Pat. No. 2,260,051 of Pardee discloses a traffic separator. A mechanism for providing variable capacity highways is also disclosed in a U.S. Pat.No. 2,287,685 of Jelinek.
A more recent U.S. Pat. No. 4,017,200 of Woods discloses a highway lane divider barrier and apparatus for shifting traffic from one lane to another in order to accommodate different traffic flow patterns for different times of day and different traffic conditions. It has been recognized that many highways that extend to and from urban areas are multiple lane highways and that it is common practice to arrange the direction of flow on such highways to expedite the traffic flow for all conditions. For example, in a six lane roadway it is common to utilize four lanes for traffic flow toward the urban area during morning hours, the other two lanes being for traffic leaving the urban areas, and then, to reverse the traffic flow during the evening hours so that four of the six lanes carry traffic away from the urban area.
The aforementioned approaches to traffic control are and have been effective for speeding up traffic and reducing congestion. However, such approaches have not addressed a serious problem of congestion at traffic intersections. The problem with intersections is that with population growth and an increase in the number of cars on the road, the problems become more and more serious. There are essentially two approaches to relieving traffic congestion at intersections. For example, a stop light can be reprogrammed to provide a much longer green light in a direction of maximum flow. The other approach is to place a police officer in the intersection to direct traffic.
It is now believed that the problem of congestion at an intersection can be reduced by the present invention that converts an intersection into a roundabout during periods of heavy traffic.